Security & Performance Audit of Our AI SaaS Before Launch (Next.js, Node.js, PostgreSQL)

We are a small startup with an AI SaaS web app that is close to launch. The app works, but nobody outside our team has ever looked at the code, and before we put real users and real money on it we want an independent technical audit. What we want from you: - Go through the codebase: security first (login, user data, API access, secrets), then performance (slow pages, database queries) - A written report we can act on: each problem, how serious it is, and roughly what it takes to fix - An honest verdict on what is worth fixing before launch and what can wait We do NOT want a rebuild and we do not want a 40-page generic checklist. We want a senior developer's eyes on our actual code and a short practical report. We can sign an NDA and give repo access. Stack: Next.js front end, Node.js back end, PostgreSQL, OpenAI API. Please share an example of an audit, review, or fix plan you have prepared for a client before.